diff --git a/main/src/main/scala/sbt/internal/Continuous.scala b/main/src/main/scala/sbt/internal/Continuous.scala
index cd6682433..39420a1fa 100644
--- a/main/src/main/scala/sbt/internal/Continuous.scala
+++ b/main/src/main/scala/sbt/internal/Continuous.scala
@@ -178,7 +178,7 @@ private[sbt] object Continuous extends DeprecatedContinuous {
     val repository = getRepository(state)
     dynamicInputs ++= inputs
     logger.debug(s"[watch] [${scopedKey.show}] Found inputs: ${inputs.map(_.glob).mkString(",")}")
-    inputs.foreach(i => repository.register(i.glob))
+    inputs.foreach(i => repository.register(i.glob).foreach(_.close()))
     val watchSettings = new WatchSettings(scopedKey)
     new Config(
       scopedKey.show,
@@ -462,7 +462,7 @@ private[sbt] object Continuous extends DeprecatedContinuous {
       if (trackMetaBuild) {
         state.get(CheckBuildSources.CheckBuildSourcesKey).flatMap(_.fileTreeRepository) match {
           case Some(r) => buildGlobs.foreach(r.register(_).foreach(observers.addObservable))
-          case _       => buildGlobs.foreach(repo.register)
+          case _       => buildGlobs.foreach(repo.register(_).foreach(_.close()))
         }
       }
 
@@ -505,6 +505,7 @@ private[sbt] object Continuous extends DeprecatedContinuous {
       override def close(): Unit = {
         configHandle.close()
         handles.forEach(_.close())
+        observers.close()
       }
     }
     val watchLogger: WatchLogger = msg => logger.debug(msg.toString)
diff --git a/main/src/main/scala/sbt/internal/nio/CheckBuildSources.scala b/main/src/main/scala/sbt/internal/nio/CheckBuildSources.scala
index 0bd9ad1fc..95e64d22b 100644
--- a/main/src/main/scala/sbt/internal/nio/CheckBuildSources.scala
+++ b/main/src/main/scala/sbt/internal/nio/CheckBuildSources.scala
@@ -75,13 +75,13 @@ private[sbt] class CheckBuildSources extends AutoCloseable {
           val repo = FileTreeRepository.default
           repo.addObserver(_ => needUpdate.set(true))
           repository.set(repo)
-          newSources.foreach(g => repo.register(g))
+          newSources.foreach(g => repo.register(g).foreach(_.close()))
         case r =>
       }
     }
     val previousSources = sources.getAndSet(newSources)
     if (previousSources != newSources) {
-      fileTreeRepository.foreach(r => newSources.foreach(g => r.register(g)))
+      fileTreeRepository.foreach(r => newSources.foreach(g => r.register(g).foreach(_.close())))
       previousStamps.set(getStamps(force = true))
     }
   }
diff --git a/main/src/main/scala/sbt/nio/Settings.scala b/main/src/main/scala/sbt/nio/Settings.scala
index 8514a6d29..f0e5f139d 100644
--- a/main/src/main/scala/sbt/nio/Settings.scala
+++ b/main/src/main/scala/sbt/nio/Settings.scala
@@ -149,7 +149,7 @@ private[sbt] object Settings {
       // This makes watch work by ensuring that the input glob is registered with the
       // repository used by the watch process.
       state.value.get(globalFileTreeRepository).foreach { repo =>
-        inputs.foreach(repo.register)
+        inputs.foreach(repo.register(_).foreach(_.close()))
       }
       dynamicInputs.foreach(_ ++= inputs.map(g => DynamicInput(g, stamper, forceTrigger)))
       view.list(inputs)